Spring suspension system for vehicles



Oct. 12, 1954 w. BENNETT mm. 2,691,519

SPRING SUSPENSION SYSTEM FOR VEHICLES Filed Aug. 18, 1952 s Sheets-Sheet 1 m 6 Z n /11 44 W B Illll iiiii TEPHE ,gigvgif 68 A TTOQNE Y5- Oct. 12, 1954 w. BENNETT ETAL 2,691,519

SPRING SUSPENSION SYSTEM FOR VEHICLES Filed Aug. 18. 1952 s Sheets-Sheet 2' ATTOQNEY.

Oct. 12, 1954 w. BENNETT ETAL 2,591,519

SPRING SUSPENSION SYSTEM FOR VEHICLES Filed Aug. 18, 1952 s Sheets-Sheet :5

IIIIII [VIII/"IN Jill/"1001M W 2;, 2b, MATE/2 BENNETT,

67'EPHEN RAE/ 51? INVENTORS.

A TTOQNE Y5.

" systems for vehicles. v v vention have to do-with the mounting; shackling Patented Oct. 12, 1954 UNITED STATES PATENT OFFICE SPRING SUSPENSION SYSTEM FOR VEHICLES Walter Bennett, L os 'Angeles, and Stephen Barker,

Alhambra, Califi, 'assignors to Utility Trailer Ma'nufacturing Company; Los- Angeles, Calif; a corporation of California Application'August 18, 1952 Serial No. 305,052

' 4 Claims. (Cl.-267-30') This invention relates to spring suspension Certain aspects of the inand the functioning of the vehicle suspension spring (here, the primary spring) whether or -not a supplemental or overload spring is used in the system. And certain other aspects of the invention have to do with the inclusion in the system' of a supplemental spring such as'is shown in, and of itself is the subject 'matter of, another prior after. -plishments of the invention will be best underapplication identified here- Those and other aspects arid accomstood from" the following detailed description of certain preferred forms of the invention shown in the accompanying drawings, in which:

Fig. 1 is a schematic plan showing a vehicle axle carried by two spring units'in accordance withthe invention;

Fig. 2 is a sectional elevation taken" as' on line 2-4 of Fig. 1, showing one spring unit and its mountings;

Figs. 2a" and 2b show the left hand portions of Fig. 2 in positions of"progressivelygreater "spring deflection under load;

lg; 3 is a cross-section on line 3 3 of Fig. 2; "Fig.- 4 is a section on line 4-4" ofFig. 1, and

Fig. 5 is a section on line 5' 5 of.Fig'. 4'.

Fig. 1 of the drawings depicts in schematic plan the general layout of two spring units" l0 and l I, and axle I2- or other equivalent load bearing member to which theya'refixedly attaehed-;'- indicating their end" mounting shackles orbracketsat'A, B; Canal D"; Fig. 2 shows the preferred structure and arrangement of one of thecompo'site spring units -and'the mountings o'ftli'eu'ni't I I) at-A-and B Mountings- A and- C,

ashore-shown, aresuch as to'position' thespring units l ll andl l 'longitudinally and thus"to locate axlel-2.- The mountings at B and are" therefore: such -as 150' allow relative longituolina-l movements of their spring ends. at B and D" are here shownas being mounted Those mountings directly on the vehi'cle frame (13in Fig. 2) but,

as will? be readily understood from what follows,

thosezmountings at B and D might well be on "seats'25' which are here formed by the down- I D l j spring shackle" 32: to be set fixedly in a" longitufdinally adjusted position on the vehicle" frame.

, 2 overloads'pring leavesm, here'preferably shown as three'le'aves which preferably" lie at their centers directly on the center portion of the primary spring, which are preferably shorter than the upper leaves of theprimary and lie on the" primary leaves throughout their lengths when all the leaves are under little or 'no' load.

The three supplemental'leaves 2| may be, as

Shown, of substantially" equal lengths and" their outer endslie' under"downwa'rdly facing spring wardly" facing end surfaces of seat members 26 -Fig.' 2* shows the mountings" of the spring unit lfl and shows that unit under no load or under a minimum load such as that" of the unloaded vehide. The center of the Whole Sp'lin'g unit [0 i'sfiXe'd'ly attached to axle l2 in any suitable manner, as by a clamping means involving-yoke 'bol'is eo so" that thefa'xl'e fixed with relation to the spring and" longitudinalad'justm'ent of spring position" on the vehicle fram'e'will' corre'spondingly ad jus't and set the" fore and" an position of the associated end of the axle. The left" hand end of spring" unit I0" isrnounted in a Thepreferredistructureof that mounting's'hackle is shown in" Figs. 2' an 3". v

The adjustablesha'ckle'mounting for the spring shovifn' in those figures comprises as main parts 'theshaekle base 3 4 which is welded to' the under face of vehicle frame I 3; an adjustable shackle member" SFWhich' seats upwardly on basetfl} a sliderf38 whic'li" and seats upwardly on base 34 and is adjusted in" position byjan" adjusting screw '40)" several rubber spring-seat blocks 42 and *and s'haekle in adjusted position'on" the shackle base. The shacklebase, secured rigidly to the vehicle frame, is of gne'r'alboi'; formation with lower bearing faces against which the shackle '36 and slider 38 'bear upwardly. Slid'er'38 is welded to adjusting screw at which extends loosely through openings 52' in the end walls of thrust of shackle" and slider' n'o'tfcarried by thescrew. Nuts 54 on'the ends ofth'e screw Serve t0"Set slider 38' in desired longitudinal "position. Shackle member'36'; asseen from Figs.

2 and 3, is of general box form and surrounds slider38i Longitudinal adjustment of the-slider therefore-effectslongitudinal adjustment ofposition' of shackle member if the: clamping bolt-'48 is-loosened: Afterad'justment of the longitudinal 3 position, setting up the nuts 56 on the clamping bolt then clamps member 36 tightly to 34 and thus sets 35 and 38 in the longitudinally adjusted position. Shackle base 34 has an interior web 34a over which U-bolt 48 passes.

The ends of spring leaves 2%, 20b and 200 project into the interior of the box-like shackle member 36 through an opening 360; in one of its walls. The extreme end of upper leaf 26a is turned up, the extreme end of lower leaf 200 is turned down, while the end of 26?) projects straight. The rubber block 42 lies under slider 38, over the end of 202; and between the upturned end of 261m and wall 35b of the shackle member. Rubber block 44 lies over 20a, under slider 38 and between the upturned end of 28a and a downturned end lip 38a of slider 38. The third rubber block 46 lies under leaf 200, between it and lower wall 35d of shackle member 36 and between the downturned end of 240 and the opposite end wall 360 of the shackle. In the load condition of Fig. 2 (minimum load on the springs) all three rubber blocks are under a substantial degree of vertical precompression. And the upper blocks 42 and 44 are also under a substantial degree of longitudinal pre-compression. And the free vertical dimension of left hand block 42 is approximately the same as that of right block 44; so that, in the spring position of Fig. 2 with the left hand end of leaf 2% projecting up to compress the left hand end of block 42 more than block 44 is compressed, the load imposed through the rubber blocks onto the spring is largely taken by the extreme outer end of 2612, giving a relatively soft spring action.

Longitudinal positioning of the spring, and therefore of the axle end to which the-spring is attached, is effected primarily by the holding of upturned leaf end 20:: between the two upper blocks 42 and 44 which are preferably pre-compressed longitudinally. The axle positioning, although always having the yielding quality of the rubber blocks, can be increased in its rigidity to any desired degree by increasing the longitudinal dimensions and therefore the longitudinal pre-compression of those rubber blocks. That rigidity is preferably such that in normal operation the end of leaf 2012 will not contact wall 36b, although that wall does form a final positive stop to the relative movement of the spring toward the left in Fig. 2. And the downturned outer end of 200 engaging lower block 46 on any excessive movementof the spring toward the right, effectually limits that relative movement. It may be remarked that, particularly where this described spring suspension is applied to a trailer, the left hand end in Fig. 2 is usually the end toward the front of the trailer; although that is not always necessarily The preferred mounting for the forward end (left hand end in the figures) of the opposite spring unit ll, is shown in Figs. 4 and 5. That mounting may be a duplicate of the longitudinally adjustable mounting of the forward end of spring unit H); but, seeing that longitudinal adjustment of only one end of the axle is necessary for aligning the axle at right angles to the vehicle axis, the forward end mounting of unit ll omits adjustability in the interest of simplicity.

Spring unit Ii is a duplicate of unit It and corresponding parts are similarly numbered. The end formations of the spring leaves 20a, Zllb and 280, and their relations to the rubber blocks 42, 44 and 46, are the same as has been explained for Fig. 2. The rubber blocks are confined in a shackle formation 82 which presents an internal fixed wall 64 in a position corresponding to that of slider 33 in Fig. 2, to present the same downwardly facing seat surfaces for the blocks 42 and 44. The bottom of shackle 62, corresponding in position to wall 38d of Fig. 2 and presenting the same seat for block 46, is formed by a bottom plate 56 held in place by bolts 53. The structure and functioning of the shackle 62, forming the mounting at C, Fig. l, for the left hand end of spring unit H, are the same as for the mounting at A for the left hand end of unit ill, except for longitudinal adjustability.

The two spring mountings at positions B and D (Fig. l) for the right hand or rear ends of the two spring units it and I l are duplicates and, as shown in the right hand portion of Fig. 2, are, in their shackle structure, the same as that of Fig. 4. The shackle 62 has the same internal wall (54 and the same bottom plate 66, supporting and confining the several rubber blocks 42, 44 and 45 in the same manner. The onlydifference is in the fact that spring leaves 243a and 200 do not have upturned and downturned ends. The three upper leaves 26a, 20b and Ne project straight through the shackle between blocks 42 and 44 on top and 46 on bottom. These spring leaves, although thus confined vertically by the vertically precornpressed rubber blocks the same as in shackle 32 or 52 (at positions A and C of Fig. 1), are not confined longitudinally at all but can move longitudinally through the shackles to allow for the effective change of spring length that accompanies changing vertical deflection.

In practice, the rubber blocks 42 and 44 for the mountings at B and D are conveniently duplicates of the blocks 42 and 44 of the mountings at A and C. Those at B and D, as is apparent, might as well be single blocks of the total size of 42 and 44, so far as function at B and D is concerned. Those at B and D may be somewhat longitudinally compressed, although that is not necessary; but those at A and C are preferably longitudinally pare-compressed to some substantial degree.

The spring mountings and shacklings that have been described for primary springs 20 in positions A, B, C and D may be utilized either with or without the supplemental or overload springs 21 and their seatings 25; and, as before mentioned, the mountings of the right hand ends of the primary springs 2B may be on rocker arms in a two axle assembly. But the particular rubber block mountings of the primary springs lend themselves well to the function of progressive spring loading when used in combination with the supplemental or overload springs; as will now be explained. For this purpose, reference is had particularly to Figs. 2, 2a and 217. These figures illustrate the progressive spring loading conditions which obtain specifically at mounting A of Fig. 1 as loads are increased; but the following applies to all four spring mountings.

Fig. 2 represents the deflection position of the spring unit under minimum load; typically under the dead load of the unloaded trailer. In that condition, the upper supplemental leaves 2! preferably, though not necessarily, rest, without being under any appreciable strain, upon the uppermost primary leaf 2011; that is, they have substantially the same free curvature as the lower primary leaves. The outer ends of leaves 2| lie shorter and the spring stifier.

1 2| whichlie under 'medial portion of primary 29. :From that position'on, under. further load and deflection; the

aspaced. below. the. supplemental. ,spring: seat- .25.

The primaryleaves 20, .in that. condition, r-bear thausual relationto each other-:-they-all:-have .substantially the same .free curvature.

, Fig.2ashows atypicalspring position. in which the. primary .spring. leaves 2 are: deflected: under a load that brings frame [3 down-by-such an -As "theload-has increased'from that of' Fig. 2

. tothat of Fig. 2a and asthe outer portions of primary-leaves 2!! become more nearlyhorizontal, rubber block 42 is relatively'de-compressed while :blOCk' 44-is relatively more greatly compressed. Assuming that the two blocks have such rela- --tive vertical dimensions that'in the condition of Fig. 2 the vertical compression of one bears any definite ratio '(say'unity) to that .of the other, then upon spring deflection which. lowers the outer end of b under 42,.rnore than the outer part of 20a is lowered under 44,'the 'center'of load pressure on the spring has moved toward the center of the-spring. Thus, in the condition-of 'Fig. 2 the load center may be approximately at 1 LI, in Fig. 2a at approximately L2, and in Fig. 2b

where the spring is further deflected; approximately at L3, insofar as load imposed through blocks 42 and; 44 is concerned. Thus, as the spring deflection increases under increasingload,

the efiective length of the primary spring becomes That action is true of the spring mountings at B, C and D (Fig.

- 1) as well as ofthe mounting at A.

The springsystem reaches the condition of Fig. 2a, where-the supplemental spring 2l'beginsto take a part of the load, when the vehicle frame and the primary sp-ringmountings have moved down approximately the distance (Def I) which supplemental spring 2 I in unstressed condition, lies below-seat 25.- On further downward movement, the part of primary spring as directly under the supplemental seat 25. and thepartof supplemental spring 2| does notmo-ve' down -as fast as the outer ends of the supplemental spring. Consequently; in somesuch' position as shown in Fig. 2b, where typical total deflection offra'me l3 is indicated by Def. 2, theouter parts of seat set down again-on the major portion. or all, of the load is supported through seat 25 and the combined spring 20, 2| acting at the short length of the supplemental spring and therefore at maximum stiffness. In

setting down on spring 20, the upper supplemental spring 2! sets down progressively from the spring center out, so that the stiffness of the supplemental spring progressively increases as it reaches the position of Fig. 2b.

The relation of supplemental spring 2! to primary spring 29 and to supplemental seat 25, so that the load on supplemental spring 2! is partially transferred to and carried by primary spring 2!! at shortened length as the supplemental spring sets down on the primary, is, in itself, and in combination with, broadly. the seating for the primary spring which causes its effective length to shorten as the load increases. not claimed in this application: being the subject matter of application Ser. 233.311, filed June 1951, by Walter Bennett. The primary spring mountings which are here described; and the cooperative dimension sufficient to at least-fill thevertical functioning of the primary and supplemental 6 springs,.mountingsand seats nowto her-described, arethe subject matters. of claims here.

In: such I a relative position :of the. springs, mountings and: seats .1 as shown in Fig. 2b',-- with the supplemental seat 25 in effect .p-ressingdown on the medial portion ofprimary2llat a -point directly below the seat, further depression .of seat 25 by any given amount tends'to cause depression of the outer ends of primary 20 bya greater amount. Rubbertblock 46; which hasa-vertical space between lower leaf 20c and the bottom shackle wall inthe condition of Fig. 2 or 2a (or it may preferably be vertically pre-compressed in those conditions) opposes that. additional: down- 1 wardmovement of the outer. end of the-primary spring. Thus,in about the condition of Fig. 2b, and in conditions of still greater loaddeflection, 'themajor portion orall of the-direct: load is taken by the combined spring 20, -2l at about'th load location indicated by L4 in Fig. 211; or by the primary alone; at L4, if the supplemental spring '2! is not used. In either case the'lowering of primary '20 at L4 under'seat 25 causes the outer end' of 20 to lower; or tend "to lower, more than at L4. The relative lowering of the outer-ends of 20a"-20c relatively takes the load L3 off the blocks 42 and 44', de-compressing those blocks and compressing block 46 on seat 3601. Block 46' then exerts aforce such as indicated by L5 on 200, opposing the relative lowering-ref 200. Thus, in such a condition of spring deflection, the deflection is not only opposed by the spring action of the primary 20, or of the-combined spring 20, 2|, acting at a shortened-length from its center determined by the position of L4, but also by'the stressed spring action in the length ofprimary leaves 20a, 17 and c lying between L4 and L5. The action there is that of the endmoment of-a continuous beam.

That action does not necessarily depend on supplemental spring 2 l being present, ashas been indicated above. For instance, ift-he spring function of 2! isignored. the leaves 2! may be regarded' merely as filler between seat 25 and upper main :le'af 2M". or in eifect as an extension of 25. In either of those 'circumstances'the' last described action of the outer parts of the primary spring will take place.

We claim:

' 1. In combination with. a vehiclesupportin leaf spring which has free end which extends in a generally horizontal direction. shackle means mounted on the vehicle frame and engaging the free spring end. said shackle means embodying 'a box-like shackle structure with upper and lower walls above and below the free spring end, the free spring end having an upturned end portion and also a portion extending longitudinally beyond the upturned portion, and the shackle structure having and walls located spacedly at opposite sides of the upturned end portion, a pair of rubber blocks held in the shackle structure between the upper face of the spring end and the upper shackle wall, the two blocks being held at opposite sides of the upturned spring end and between it and the end walls, and a third rubber block held in the shackle structure between the lower face of the spring end and the lower shackle wall, all said blocks being held in Vertical precompression and the two upper blocks being held in horizontal pre-compression between the two end walls.

2. In combination with a vehicle supporting leaf spring which has a free end extending in a generally horizontal direction, the spring end having an upturned and a downturned portion and also a portion extending longitudinally beyond the unturned portion, a box-like shackle structure with upper and lower walls above and below the free spring end and with end walls lying at opposite sides of the upturned and downturned spring end portions, means for setting said shackle structure in a longitudinally adjusted position on the vehicle frame, a pair of rubber blocks held in the shackle structure between the upper face of the spring end and the upper shackle wall, the two blocks being held at opposite sides described for supporting a vehicle frame on a load supporting member, comprising the combination of a primary leaf spring having its base portion attached to the load supporting member, shackle means mounted on the vehicle frame and engaging the free outer end of the primary leaf spring for imposing frame-supported load thereon and also acting to limit downward movement of said free outer end with relation to the frame, other means connecting the spring to the vehicle frame and acting to oppose rotation of the base portion of the spring in a vertical plane, a relatively short supplemental leaf spring attached to the load supporting member and lying with its free end directly above an intermediate point in the length of the primary spring and adapted to seat downwardly on said intermediate point when the ends of both springs are depressed under load, a downwardly facing load-applying seat associated with the vehicle frame and adapted to bear down on the free end of the supplemental spring, the free end of the supplemental spring when under relatively light load being normally spaced above said intermediate point of the primary spring by such distance as to move down into load applying engagement with the intermediate point of the primary spring under relatively heavier loads, all whereby the primary spring takes heavier loads from said downwardly facing load-applying seat through the free end of the supplemental spring at a relatively shortened spring length, and whereby a continuous beam moment is set up in the primary spring in its length between the end shackle means and said intermediate point in its length under the load applying seat.

4. In combination with a vehicle supporting leaf spring which has a free end that extends in a generally horizontal direction, the free end of the spring having an upturned end portion and also a portion extending longitudinally beyond the upturned portion, a shackle means mounted on the vehicle frame and engaging the free spring end, said shackle means comprising a shackle base secured to the vehicle frame, a box-like shackle member having an open upper end and having an upper surface seating upwardly on a lower surface of the base and having a lower wall and end walls, a slider confined longitudinally between the end walls within the upper open end of the box-like shackle member and seating upwardly on a lower surface of the base, both the shackle member and the slider adapted to slide longitudinally on the base, means adjustably setting the position of the slider and of the confining shackle member on the base, means clamping the shackle member against the lower face of the base, said box-like shackle member receiving the end portion of the spring and having two spring confining rubber blocks lying between the slider and the upper face of the spring and between the upturned portion and the end walls, and another rubber block lying between the shackle bottom wall and the lower face of the spring, all said blocks being held in vertical precompression and the two upper blocks being held in horizontal pre-compression between the end walls and the upturned spring portion.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,496,237 Leipert June 3, 1924 2,054,305 Stilwell Sept. 15, 1936 FOREIGN PATENTS Number Country Date 231,960 Great Britain Apr. 16, 1925 249,651 Great Britain Apr. 1, 1926 503,874 Germany July 28, 1930 966,729 France Mar. 8, 1950 

